AFR Safety Settings - Polarity?

[AbeFM]

I didn't see a way to alter the polarity on the AFR safety outputs. Since the spark outputs are low current, I put in an NPN buffer (before I knew what I was going to use them for), and now AFR warning (AWESOME feature, btw) lights my light when things are ok and turns it off when they are not.

I propose that be added as an option - though if I just missed it, er, where is it?

[billr]

I guess I'm confused... it looks to me like the existing AFR Safety can kill either the fuel or spark, or both. What else are you looking for?

[AbeFM]

Ah! I should have been more clean - I just mean the indicator light!

I'm not actually using it as a safety right now so much as a better way to keep an eye on things. A gauge is too much to look at, constantly having to check boost and rpm to know what you're supposed to be at. I suppose an IDEAL output would be an AFR-error gauge (add it to the list - AFR-error, FuelPressure-error, VVT-error, etc etc)...

But the light is just fine, I can set it to be what I want... The only issue, as mentioned, is that it turns off instead of on when I want it the other way around - to light up when there's a situation and to just leave me alone the rest of the time.

[jsmcortina]

It should already be doing what you are asking - lighting if there's a problem.

MSQ ?

James

[AbeFM]

Er, I have it turned off right now - but it behaves as you'd expect - it agrees with the "AFR WARNING" indicator in TS.

But the light is on when off and off when on. It's the same circuit I use for lighting up when there is knock retard, but there I can select polarity. I can re-set-up AFR warning if you'd like.
-Abe.

[jsmcortina]

I can only assume that you have a wiring error. I just tested on the stim using Spk H and it behaves exactly as it should. When the AFR safety kicks in, the pin puts out 5V and lights up the LED.

James

[AbeFM]

That's exactly what I'm saying. It would be nice to have the ability to alter it in software. Mine isn't wired "wrong" it's just wired - in this case, active low.

I used an NPN because the outputs were not rates for the kinda currents a large LED or any regular light would take, so I put a buffer in there.

I'm not trying to make anyone defensive, I'm requesting a feature which I think would be useful in general - when you have a low power output, you don't run big bright lights off of it. The other generic outputs recognize this, but not this one, I'm asking if it could be brought inline with the other outputs.
-Abe.

[billr]

So, why can't the warning light be wired the other way? If it already has a supply voltage to it, and you are looking for an open-collector type ground to turn the light on, just changing polarity of the MS output may not work. I don't know that specific circuit, but it may not be pulling to a hard ground when low, it may be floating; and it certainly doesn't sound like it is open-circuit when "high", it is connecting to the +5V supply.

[AbeFM]

It's wired to use the stock lights from the original car - i.e. npn to ground, being fed with +12V. Some of them are LED retrofits, some are the OEM incandescent lights. I can always put a SECOND transistor in there to invert the signal again, but it's a lot more work than checking a "polarity" box in software - especially since I have all my left over sparks set up that way. As "generic outputs" I can set them that way. Perhaps I can set up a generic output that turns on when AFR warning is off. Is there a status bit I could watch for this?


As far as keeping it from taking actions (warning only) mode) burring protection - I just set:

"kill sparks" for 0 sec
TPS below 110%
MAP below 400
RPM below 9000

All of which are the extreme values allowed - the 9k is technically something I could be over but I wasn't that worried. Still, a "indicator only" mode would be nice for daily driving just to see how the tune is behaving, and "Warning output inverted" would also be awesome!

[jsmcortina]

You are going to have to post a circuit diagram of your circuit to explain how it doesn't work.

The AFR safety system puts 5V on the spark pins when it is active. (i.e. it already does what you are asking for.)

As a warning only mode, you could configure an On/off output based on the value of "AFR1 error".

James

[AbeFM]

Ah, awesome, thanks!! "AFR1 error" will work only when AFR-safety is enabled? Does it use the same AFR difference table?

As to the circuit, it's inverting - I was just hoping to be able to SET to polarity in software. Thank you.
-Abe.

[jsmcortina]

Actually, scrub that. I just checked and then found that "AFR error" is a calculated field in TunerStudio (ini file) so you can't use it for the on/off outputs. (Currently!)

I can't help with your circuit if you keep it secret.

James

[AbeFM]

Too bad about the variable, that would be excellent!

The circuit is just a standard NPN inverting circuit, to find out I'd have to pull my dash apart.


That's the best I can do right now, but I think I took it out and tweaked it since. Currently I'm using one for Low Battery, and another for Knock Retard > 1 degree or something. Power On Value "ON", Active Value "Off".

I'm not confused on the circuit, it's just not how I built them.

[jsmcortina]

The LED driver transistors are "inverting" but successfully light the LEDs when the CPU outputs 5V.

James